Hitachi Global Storage Technologies has announced the industry's highest density, single-platter hard disk drive that has an areal density of 636Gbit/inch, almost 100Gbit per square inch more than its closest competitor.

The Travelstar Z5K500, which comes in 500GB, 320GB and 250GB models, is the second second generation of Hitachi products to use the company's Advanced Format drive, which increases the physical sector size on drives from 512 bytes to 4,096 (4K) bytes, thereby improving drive capacity and error correction capabilities.

"Ultra thin and light devices are, without argument, a growing trend. In order for these innovative designs to live up to their true potential, they need rugged, reliable high-capacity hard drives that can withstand the rigors of a portable environment and satisfy the storage demands of their end users, and Hitachi continues to deliver," said Brendan Collins, vice president of product marketing at Hitachi GST, in a statement.

Collins said the Perpendicular Magnetic Recording technology it's using to produce high-capacity drives today will allow the company to increase capacity on their 3.5-in drives as well. Currently, Hitachi sells a 3TB, 3.5-in desktop drive. "If we continue on this trend, we could ship a 4TB or 5TB drive in the next year or two," he said.

As far as 2.5-in drives go, the areal density has been increasing about 25% per year, he said, meaning it will be a few years before the company produces a single-platter 1TB 2.5-in drive. However, it would ship a two-platter drive anytime it wants. But, the 500GB capacity point is the up and coming sweet spot in the market, he added.

"This is more of a technology statement rather than anything else," Collins said. "It does open up all sorts of options."

Western Digital was first to the table with a 1TB laptop drive last year. That Scorpio Blue drive, however, contained three 333GB capacity platters and measured 12.5mm in height. Toshiba then followed with their own three-platter, 12.5mm 1TB laptop drives, along with two-platter 750GB 9.5mm-high drives. Seagate's highest capacity laptop drive is a three-platter, 750GB drive.

Hitachi said its new drive surpasses per-gigabyte cost advantages that other 2.5-in and 1.8-in drives had offered. Of course, it also exceeds the price per gigabyte when compared to solid-state drives, as well.

The drives are aimed at system manufacturers who can use the thinner drives to differentiate product lines by utilizing space savings to produce thinner devices, add battery capacity, increase shock robustness, or improve internal airflow.

The Travelstar Z-series of drives also offer an optional bulk data encryption feature, which allows the drives to be set to encrypt all data stored on them. The drives are expected to ship to distributors this month.